The Astrophysical Journal最新文献_第3页

A Possible Common Physics Picture Reflected by the Gamma-Ray Emission of the Galactic Center 银河系中心伽玛射线发射所反映的可能的共同物理图像

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade3ce

Lin Nie, Yi-Qing Guo and Si-Ming Liu

{"title":"A Possible Common Physics Picture Reflected by the Gamma-Ray Emission of the Galactic Center","authors":"Lin Nie, Yi-Qing Guo and Si-Ming Liu","doi":"10.3847/1538-4357/ade3ce","DOIUrl":"https://doi.org/10.3847/1538-4357/ade3ce","url":null,"abstract":"Long-term observations of the Galactic center by Fermi and HESS have revealed a novel phenomenon: the high-energy gamma-ray spectrum from the gamma-ray source HESS J1745-290 exhibits a double power-law structure. In this study, we propose a new explanation for this phenomenon. We suggest that the low-energy (GeV) power-law spectrum originates from interactions between trapped background “sea” cosmic ray particles and the dense gaseous environment near the Galactic center. In contrast, the bubble-like structure in the high-energy (TeV) spectrum is produced by protons accelerated during active phases of the Galactic center, through the same physical process. Based on this framework, we first calculate the gamma-ray emission generated by cosmic ray protons accelerated in the Galactic center. Then, using a spatially dependent cosmic ray propagation model, we compute the energy spectrum of background “sea” cosmic ray protons and their associated diffuse gamma-ray emission in the Galactic center region. The results closely reproduce the observations from Fermi-LAT and HESS, suggesting that their long-term data support this picture: high-energy cosmic rays in the local region originate from nearby cosmic ray sources, while low-energy cosmic rays are a unified contribution from distant cosmic ray sources. We anticipate that this double power-law structure may be widely present in the halo of a Galactic cosmic-ray source or a slow-diffusion region. We hope that future observations will detect more such sources, allowing us to further test and validate our model.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"669 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Discovery of a Giant Molecular Cloud at the Midpoint of the Galactic Bar Dust Lanes: M4.7–0.8 在银河系尘埃带的中点发现一个巨大的分子云：M4.7-0.8

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/adc687

Natalie O. Butterfield, Larry K. Morgan, Ashley T. Barnes, Adam Ginsburg, Savannah Gramze, Mark R. Morris, Mattia C. Sormani, Cara D. Battersby, Charlie Burton, Allison H. Costa, Elisabeth A. C. Mills, Jürgen Ott, Michael Rugel and Harrison West

{"title":"Discovery of a Giant Molecular Cloud at the Midpoint of the Galactic Bar Dust Lanes: M4.7–0.8","authors":"Natalie O. Butterfield, Larry K. Morgan, Ashley T. Barnes, Adam Ginsburg, Savannah Gramze, Mark R. Morris, Mattia C. Sormani, Cara D. Battersby, Charlie Burton, Allison H. Costa, Elisabeth A. C. Mills, Jürgen Ott, Michael Rugel and Harrison West","doi":"10.3847/1538-4357/adc687","DOIUrl":"https://doi.org/10.3847/1538-4357/adc687","url":null,"abstract":"We present the detection of a previously unknown giant molecular cloud (GMC) located at the midpoint of the Galactic Bar Dust Lanes (M4.7–0.8), using spectral line observations taken with the Green Bank Telescope. This ∼60 pc long GMC is associated with accreting material that is transitioning from the quieter Galactic disk environment to the more extreme central molecular zone (CMZ) environment. Our 24 GHz single-dish radio observations targeted the NH3 (1,1)−(4,4) and HC5N (9−8), known dense gas tracers. The observations reveal the main features of the GMC, which we have dubbed the “Nexus” and “Filament,” covering a 0 5 × 0 25 area at 31″ angular resolution. In this publication, we investigate the gas kinematics within the observed region and compare the distribution of molecular emission to previous infrared surveys to better understand the dust component. The observed gas tracers show centrally condensed cores corresponding to the positions of high dust column densities and low dust temperatures. We report the detection of a previously unknown NH3 (3,3) maser, along with a 70 μm source association, which supports the identification of this region as being actively star-forming. Gas emission in this region shows broad linewidths, comparable to values seen in CMZ clouds. The overall description of this cloud that we present is that of a highly dynamic region comprising dense gas and dust. This encapsulates a wide range of features associated with star formation, in addition to material transport related to the CMZ.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

C-19 and Hot, Wide Star Streams C-19和又热又宽的星流

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade4ce

Raymond G. Carlberg, Rodrigo Ibata, Nicolas F. Martin, Else Starkenburg, David S. Aguado, Khyati Malhan, Kim Venn, Zhen Yuan and 珍袁

引用次数: 0

Integrated Galaxy Light from Stacking 105 Random Pointings in the Dark Energy Survey Data 暗能量调查数据中105个随机点叠加的综合星系光

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade309

Jenna E. Moore, Seth H. Cohen, Philip Mauskopf and Evan Scannapieco

引用次数: 0

Saturns, but Not Super-Jupiters, Occur More Frequently in the Presence of Inner Super-Earths 土星，而不是超级木星，更频繁地出现在内部超级地球的存在下

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade715

Etienne Lefèvre-Forján and Gijs D. Mulders

{"title":"Saturns, but Not Super-Jupiters, Occur More Frequently in the Presence of Inner Super-Earths","authors":"Etienne Lefèvre-Forján and Gijs D. Mulders","doi":"10.3847/1538-4357/ade715","DOIUrl":"https://doi.org/10.3847/1538-4357/ade715","url":null,"abstract":"Studies from recent years have reached different conclusions regarding how frequently super-Earths are accompanied by long-period giant planets and vice versa. This relation has been predicted to be mass dependent by planet-formation models. We investigate that as the origin of the discrepancy using a radial velocity sample: the California Legacy Survey. We perform detection completeness corrections in order to discard detection bias as a possible explanation to our results. After bias corrections, we find that cold Jupiters are times more massive when not in the company of an inner super-Earth, while super-Earths are not significantly more massive while in the company of an outer giant planet. We also report an occurrence enhancement for Saturns (median projected mass of 0.6MJ) while in presence of a super-Earth by a factor of ∼4, and for super-Earths in the presence of Saturns by the same factor. This positive correlation disappears for super-Jupiters (median projected mass of 3.1MJ). These results show that while cold Jupiters are generally accompanied by inner super-Earths, this does not hold for the largest giant planets, such as those that will be discovered by Gaia, which will likely not be accompanied by transiting planets. The mass dependence, in combination with the different detection limits of different surveys, may explain the discrepancies concerning occurrence relations between cold Jupiters and super-Earths.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

AMUSE-Antlia. II. Intracluster X-Ray Population in the Antlia Cluster AMUSE-Antlia。2。安提亚星系团内x射线人口

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade3d4

Zhensong Hu, Yuanyuan Su, Zhiyuan Li, Meicun Hou, Ralph P. Kraft, Kelley M. Hess and Hao Chen

{"title":"AMUSE-Antlia. II. Intracluster X-Ray Population in the Antlia Cluster","authors":"Zhensong Hu, Yuanyuan Su, Zhiyuan Li, Meicun Hou, Ralph P. Kraft, Kelley M. Hess and Hao Chen","doi":"10.3847/1538-4357/ade3d4","DOIUrl":"https://doi.org/10.3847/1538-4357/ade3d4","url":null,"abstract":"We conduct a systematic survey of X-ray sources in the inner (r ∼ 200 kpc) region of the Antlia cluster based on Chandra observations, down to a source detection limit of L(0.5–8 keV) ∼ 4.2 × 10−7 ph cm−2 s−1 (2 × 1038 erg s−1). We present an X-ray source catalog with 202 sources and provide their coordinates, multiband flux information, and hardness ratios. We find a statistically significant excess at a significance level of 4.2σ with 37.6 excess sources beyond 3 times the mean effective radius of the two brightest central galaxies (BCGs). This implies that these excess sources could be a genuine intracluster X-ray population that is not associated with the bulk stellar component. Also, the increased number of excess sources in the fields containing a BCG implies a potential connection between the excess sources and BCGs. The discovery of these sources in the Antlia cluster, together with previous research of similar findings in the other two nearby clusters, Virgo and Fornax, indicates that the intracluster X-ray population could be universal in nearby galaxy clusters. Furthermore, we discuss the candidate origins of the excess sources, including low-mass X-ray binaries (LMXBs) associated with intracluster light (ICL-LMXBs), LMXBs in globular clusters (GC-LMXBs), and supernova-kicked LMXBs (SN-kicked LMXBs). We estimate that the contribution of ICL-LMXBs, which should include the LMXBs related to the stellar halo surrounding BCGs, is unlikely to dominate the intracluster X-ray population in Antlia. Meanwhile, GC-LMXBs and SN-kicked LMXBs, each component could contribute ∼30% to the total excess sources.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lyα Radiative Transfer Modeling for 163 MUSE Lyα-emitting Galaxies at z = 3–6 z = 3-6处163个MUSE Lyα发射星系的Lyα辐射传递模型

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade2da

Sangeun Yu, Hyunmi Song and Kwang-Il Seon

{"title":"Lyα Radiative Transfer Modeling for 163 MUSE Lyα-emitting Galaxies at z = 3–6","authors":"Sangeun Yu, Hyunmi Song and Kwang-Il Seon","doi":"10.3847/1538-4357/ade2da","DOIUrl":"https://doi.org/10.3847/1538-4357/ade2da","url":null,"abstract":"We utilized Lyα radiative transfer calculations from H. Song et al. to investigate the properties of extended Lyα halos around star-forming galaxies in the Hubble Ultra Deep Field, observed by the Multi-Unit Spectroscopic Explorer. Expanding on the work of H. Song et al., which was limited to eight galaxies, we derived best-fit models for a significantly larger sample of 163 galaxies, which successfully reproduced both their Lyα spectra and surface brightness profiles (SBPs). These best-fit models suggest a broad medium distribution surrounding each galaxy, with low expanding velocities at large radii. This conclusion could not have been drawn from modeling either the spectrum or SBP alone, but only through simultaneous modeling of both. Our correlation analysis between observables and model parameters reveals that the spatial extent of Lyα halos is primarily determined by the extents of the medium and the source, while the spectral peak shift and full width at half maximum are governed mainly by optical depth, with the velocity structure of the medium playing a secondary yet nonnegligible role. The fact that various correlations derived from the full set of models and those from the best-fit subset can differ significantly highlights the complex and interdependent nature of Lyα radiative transfer. All model parameters interact to shape the observed Lyα features in a nontrivial way.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multifrequency Radio Observations of the Magnetar Swift J1818.0–1607 磁星雨燕J1818.0-1607的多频射电观测

The Astrophysical Journal Pub Date : 2025-07-15 DOI: 10.3847/1538-4357/ade14f

Evan F. Lewis, Harsha Blumer, Ryan S. Lynch and Maura A. McLaughlin

引用次数: 0

Efficient Ionizers with Low H β + [O iii] Equivalent Widths: JADES Spectroscopy of a Peculiar High-redshift Population 具有低H β + [O iii]等效宽度的高效电离剂：特殊高红移种群的JADES光谱

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/adddb5

Isaac H. Laseter, Michael V. Maseda, Charlotte Simmonds, Ryan Endsley, Daniel Stark, Andrew J. Bunker, Rachana Bhatawdekar, Kristan Boyett, Alex J. Cameron, Stefano Carniani, Mirko Curti, Zhiyuan Ji, Pierluigi Rinaldi, Aayush Saxena, Sandro Tacchella, Chris Willott, Joris Witstok and Yongda Zhu

{"title":"Efficient Ionizers with Low H β + [O iii] Equivalent Widths: JADES Spectroscopy of a Peculiar High-redshift Population","authors":"Isaac H. Laseter, Michael V. Maseda, Charlotte Simmonds, Ryan Endsley, Daniel Stark, Andrew J. Bunker, Rachana Bhatawdekar, Kristan Boyett, Alex J. Cameron, Stefano Carniani, Mirko Curti, Zhiyuan Ji, Pierluigi Rinaldi, Aayush Saxena, Sandro Tacchella, Chris Willott, Joris Witstok and Yongda Zhu","doi":"10.3847/1538-4357/adddb5","DOIUrl":"https://doi.org/10.3847/1538-4357/adddb5","url":null,"abstract":"Early JWST photometric studies discovered a population of UV-faint ( ) z ∼ 6.5–8 Lyman break galaxies with spectral energy distributions implying young ages (∼10 Myr) yet relatively weak Hβ + [O iii] equivalent widths (EWHβ + [O iii] ≈ 400 Å). These galaxies seemingly contradict the implicit understanding that young star-forming galaxies are ubiquitously strong Hβ + [O iii] emitters, i.e., extreme emission line galaxies (EW ≳750 Å). Low metallicities, high Lyman continuum escape fractions, and rapidly declining star formation histories have been proposed as primary drivers behind low Hβ + [O iii] EWs, but the blend of Hβ + [O iii] in photometric studies makes proving one of these scenarios difficult. We aim to characterize this peculiar population with deep spectroscopy from the JWST Advanced Deep Extragalactic Survey. We find that a significant subset of these galaxies at z ≳ 2 with modest Hβ + [O iii] EWs (≈300–600 Å) have high ionization efficiencies ( ). Suppressed [O iii] EW values yet elevated Hα and Hβ EW values imply that the level of chemical enrichment is the primary culprit, supported by spectroscopic measurements of metallicities below 12 + log(O/H) ≈ 7.70 (0.1Z⊙). We demonstrate that integrated Hβ + [O iii] selections (e.g., Hβ + [O iii] EW > 700 Å) exclude the most metal-poor efficient ionizers and favor (1) more chemically enriched systems with comparable extreme radiation fields and (2) older starbursting systems. In contrast, metallicity degeneracies are reduced in Hα space, enabling the identification of these metal-poor efficient ionizers by their specific star formation rate.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wind-fed Supermassive Black Hole Accretion by the Nuclear Star Cluster: The Case of M31* 由核星团引起的风馈超大质量黑洞吸积：以M31*为例

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade1d5

Zhao Su, Zhiyuan Li and Zongnan Li

{"title":"Wind-fed Supermassive Black Hole Accretion by the Nuclear Star Cluster: The Case of M31*","authors":"Zhao Su, Zhiyuan Li and Zongnan Li","doi":"10.3847/1538-4357/ade1d5","DOIUrl":"https://doi.org/10.3847/1538-4357/ade1d5","url":null,"abstract":"The central supermassive black hole (SMBH) of the Andromeda galaxy, known as M31*, exhibits dim electromagnetic emission and is inferred to have an extremely low accretion rate for its remarkable mass (∼108M⊙). In this work, we use three-dimensional hydrodynamical simulations to explore a previously untested scenario, in which M31* is fed by the collective stellar mass loss from its surrounding nuclear star cluster, manifested as a famous eccentric disk of predominantly old stellar populations. The stellar mass loss is assumed to be dominated by the slow and cold winds from 100 asymptotic giant-branch stars, which follow well-constrained Keplerian orbits around M31* and together provide a mass injection rate of ∼4 × 10−5M⊙ yr−1. The simulations achieve a quasi-steady state on a megayear timescale, at which point a quasi-Keplerian, cool (T ∼ 103–104 K) gas disk extending several parsecs is established. This disk is continuously supplied by the stellar winds and itself feeds the central SMBH. At the end of the simulations at 2 Myr, an accretion rate of ∼2 × 10−5M⊙ yr−1 is found but could vary by a factor of a few depending on whether the subdominant gravity of the NSC or a moderate global inflow is included. The predicted X-ray luminosity of ∼1036 erg s−1, dominated by the hot (T ∼ 107–108 K) plasma within 0.2 pc of the SMBH, is consistent with Chandra observations. We conclude that the feeding mechanism of M31* is successfully identified, which has important implications for the working of dormant SMBHs prevalent in the local Universe.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0